Automatic orientation techniques for photocontrols of intelligent lighting fixtures

Abstract

A photocontrol, such as for an outdoor intelligent lighting fixture, may detect levels of ambient light at multiple sections of the photocontrol. The ambient light may be detected via multiple photosensors located at the photocontrol sections. In addition, the ambient light may be detected via multiple color filters (or sections of a color filter) located at the photocontrol sections. The photocontrol may determine an ambient light differential, such as an instant differential between light received at the multiple photocontrol sections at a particular time, or a temporal differential between light received at the multiple photocontrol sections across multiple times. Based on the ambient light differential, the photocontrol may identify triggering photosensor or triggering section that substantially align with a geographical orientation. The photocontrol may identify a lighting output profile. An output level of a lighting element may be modified based on the lighting output profile.

What is claimed is: 
     
       1. A photocontrol for a lighting fixture, the photocontrol comprising:
 (i) a first photosensor configured to detect a first ambient light level at a first section of the photocontrol, 
 (ii) a second photosensor configured to detect a second ambient light level at a second section of the photocontrol, 
 (iii) a third photosensor configured to detect a third ambient light level at a third section of the photocontrol, wherein the first, second and third sections of the photocontrol receive various ambient light levels at various periods of a diurnal cycle, and 
 a microprocessor configured for:
 determining, at a first time period of the diurnal cycle, respective first pairwise instant ambient light differentials between first light levels detected respectively by each pair of the first, second, and third photosensors; 
 determining, at a second time period of the diurnal cycle, respective second pairwise instant ambient light differentials between second light levels detected respectively by each pair of the first, second, and third photosensors; 
 calculating a first temporal ambient light differential between the first section and the second section of the photocontrol, a second temporal ambient light differential between the first section and the third section of the photocontrol, and a third temporal ambient light differential between the second section and the third section of the photocontrol, the first, second, and third temporal ambient light differentials being based on the respective first pairwise instant ambient light differentials at the first time period of the diurnal cycle and the respective second pairwise instant ambient light differentials at the second time period of the diurnal cycle; 
 identifying, based on a comparison of the first, second, and third temporal ambient light differentials, that the first photosensor is a triggering photosensor of the photocontrol, wherein the comparison of the first, second, and third temporal ambient light differentials indicates that the first photosensor has detected ambient light levels having a least variation between the first and second time periods of the diurnal cycle; and 
 modifying, based on a fourth ambient light level detected via the triggering photosensor, an output level of a lighting element of the lighting fixture. 
 
 
     
     
       2. The photocontrol of  claim 1 , the microprocessor further configured for:
 identifying a geographical orientation of the photocontrol based on identifying the triggering photosensor. 
 
     
     
       3. The photocontrol of  claim 1 , the microprocessor further configured for:
 determining a periodicity of the first temporal ambient light differential, 
 wherein modifying the output level is based further on the periodicity of the first temporal ambient light differential. 
 
     
     
       4. The photocontrol of  claim 1 , wherein identifying the triggering photosensor is further based on a relative location of the first section of the photocontrol with respect to the second section or the third section of the photocontrol. 
     
     
       5. The photocontrol of  claim 4 , wherein the relative location includes one or more of (i) an angular separation of the first section of the photocontrol with respect to the second section or the third section of the photocontrol, or (ii) a distance between the first section of the photocontrol and the second section or the third section of the photocontrol, such that identifying the triggering photosensor is further based on one or more of the angular separation or the distance. 
     
     
       6. The photocontrol of  claim 1 , further comprising at least one additional photosensor configured to detect an additional ambient light level at an additional section of the photocontrol,
 the microprocessor further configured for determining additional respective pairwise instant ambient light differentials between the additional ambient light level detected via the additional photosensor and each of the first ambient light level, the second ambient light level, and the third ambient light level, 
 wherein the triggering photosensor further includes a combination of the first photosensor and the additional photosensor. 
 
     
     
       7. A method of orienting a photocontrol for a lighting fixture, the method comprising:
 receiving, from a first photosensor, a first data signal indicating a first ambient light level at a first section of the photocontrol; 
 receiving, from a second photosensor, a second data signal indicating a second ambient light level at a second section of the photocontrol, wherein the first section and the second section of the photocontrol receive various ambient light levels at various periods of a diurnal cycle; 
 determining, at a first time period of the diurnal cycle, a first instant ambient light differential between a first light level detected via the first photosensor and a second light level detected via the second photosensor; 
 determining, at a second time period of the diurnal cycle, a second instant ambient light differential between a third light level detected via the first photosensor and a fourth light level detected via the second photosensor; 
 calculating, based on the first instant ambient light differential and the second instant ambient light differential, a temporal ambient light differential between the first section of the photocontrol and the second section of the photocontrol, the temporal ambient light differential being between the first time period and second time period of the diurnal cycle; 
 determining, based on the temporal ambient light differential, a variation of the ambient light levels detected via the first photosensor and the second photosensor between the first and second time periods of the diurnal cycle; 
 identifying, based on the variation of the ambient light levels, a triggering photosensor of the photocontrol, wherein the triggering photosensor is identified as at least one of the first photosensor or the second photosensor; and 
 modifying, based on a further data signal indicating a further ambient light level detected via the triggering photosensor, an output level of a lighting element included in the lighting fixture. 
 
     
     
       8. The method of  claim 7 , further comprising:
 accessing a first historical sequence of ambient light levels detected via the first photosensor and a second historical sequence of ambient light levels detected via the second photosensor; 
 determining a current instant ambient light differential between the first ambient light level and the second ambient light level; and 
 determining a historical instant ambient light differential between a first historical light level included in the first historical sequence and a second historical light level included in the second historical sequence, 
 wherein calculating the temporal ambient light differential is further based on a comparison of the current instant ambient light differential and the historical instant ambient light differential. 
 
     
     
       9. The method of  claim 7 , further comprising:
 identifying a geographical orientation of the photocontrol based on identifying the triggering photosensor. 
 
     
     
       10. The method of  claim 7 , further comprising:
 determining a periodicity of the temporal ambient light differential, 
 wherein modifying the output level of the lighting element is based further on the periodicity of the temporal ambient light differential. 
 
     
     
       11. The method of  claim 7 , wherein identifying the triggering photosensor is further based on a relative location of the first section of the photocontrol with respect to the second section of the photocontrol. 
     
     
       12. The method of  claim 11 , wherein the relative location includes one or more of (i) an angular separation of the first section of the photocontrol with respect to the second section of the photocontrol, or (ii) a distance between the first section of the photocontrol and the second section of the photocontrol, such that identifying the triggering photosensor is further based on one or more of the angular separation or the distance. 
     
     
       13. The method of  claim 7 , further comprising:
 receiving, from an additional photosensor, an additional data signal indicating an additional ambient light level at the first time period at an additional section of the photocontrol; and 
 calculating, based on the additional data signal, additional instant ambient light differentials between the additional ambient light level and each of the first light level and the second light level, 
 wherein identifying the triggering photosensor is further based on the additional instant ambient light differentials. 
 
     
     
       14. A photocontrol for a lighting fixture, the photocontrol comprising:
 a color filter having multiple filter sections, each particular filter section configured to admit ambient light having a particular color, wherein each particular filter section receives various ambient light levels at various periods of a diurnal cycle, 
 a photosensor configured to generate one or more color data signals, each particular color data signal indicating an intensity of the ambient light having the particular color admitted via the particular filter section, and 
 a microprocessor configured for: 
 receiving, from the photosensor and at a first time period of the diurnal cycle, a first color data signal indicating a first intensity of ambient light having a first color admitted via a first filter section and a second color data signal indicating a second intensity of ambient light having a second color admitted via a second filter section; 
 determining, based on the first color data signal and the second color data signal, a first instant ambient light differential between the first intensity of the ambient light and the second intensity of the ambient light at the first time period of the diurnal cycle; 
 receiving, from the photosensor and at a second time period of the diurnal cycle, a third color data signal indicating a third intensity of the ambient light having the first color admitted via the first filter section and a fourth color data signal indicating a fourth intensity of the ambient light having the second color admitted via the second filter section; 
 determining, based on the first color data signal and the second color data signal, a second instant ambient light differential between the third intensity of the ambient light and the fourth intensity of the ambient light at the second time period of the diurnal cycle; 
 calculating, based on the first instant ambient light differential and the second instant ambient light differential, a temporal ambient light differential between the first filter section and the second filter section, the temporal ambient light differential being between the first time period and second time period of the diurnal cycle; 
 determining, based on the temporal ambient light differential, a variation of ambient light intensities admitted via the first filter section and the second filter section between the first and second time periods of the diurnal cycle; 
 identifying, based on the temporal ambient light differential, a triggering section of the photocontrol, wherein the triggering section is identified based on a combination of the one or more color data signals of the photosensor; and 
 modifying, based on an additional light intensity admitted via the triggering section, an output level of a lighting element of the lighting fixture. 
 
     
     
       15. The photocontrol of  claim 14 , the microprocessor further configured for:
 accessing a first historical set of color data signals indicating historical intensities of the ambient light having the first color and a second historical set of color data signals indicating historical intensities of the ambient light having the second color; 
 determining a historical instant ambient light differential between a first historical intensity of the ambient light having the first color and a second historical intensity of the ambient light having the second color; and 
 calculating the temporal ambient light differential based on a comparison of the historical instant ambient light differential with one or more of the first instant ambient light differential or the second instant ambient light differential, 
 wherein identifying the triggering section is further based on the temporal ambient light differential. 
 
     
     
       16. The photocontrol of  claim 14 , the microprocessor further configured for:
 identifying a geographical orientation based on identifying the triggering section. 
 
     
     
       17. The photocontrol of  claim 15 , the microprocessor further configured for:
 determining a periodicity of the temporal ambient light differential, 
 wherein modifying the output level is based further on the periodicity of the temporal ambient light differential. 
 
     
     
       18. The photocontrol of  claim 14 , the microprocessor further configured for:
 determining a local ambient light spectral pattern received by the photosensor; and 
 applying, during the first time period, a first filter correction set, the first filter correction set describing a spectral adjustment value for the first color data signal during the first time period. 
 
     
     
       19. The photocontrol of  claim 18 , wherein determining the local ambient light spectral pattern comprises:
 accessing a historical set of color data signals, the historical set including previous color data signals indicating historical intensities of the ambient light having each particular color admitted via each particular filter section; 
 calculating, based on the previous color data signals, a combined intensity of the ambient light admitted via a combination of each particular filter section; 
 determining a relative change in spectral content of the combined intensity of the ambient light during the first time period as compared to the second time period; and 
 determining the spectral adjustment value, wherein the spectral adjustment value indicates the relative change in the spectral content during the first time period. 
 
     
     
       20. The photocontrol of  claim 14 , wherein each particular filter section is respectively positioned at a particular section of the photocontrol, such that each particular filter section has a respective angular separation with respect to each additional particular filter section,
 wherein identifying the triggering section is further based on the respective angular separation of each particular filter section with respect to each additional particular filter section.